1. Field of the Invention
The present invention generally relates to zoom lenses and camera apparatuses, in particular to zoom lenses and camera apparatuses that are downsized and capable of exerting a high performance and a wide range magnification.
2. Discussion of the Background
In these later days, it becomes the nature of things that a digital camera that is rapidly spreading has a zooming function of a photographing lens. Accordingly, high image quality, wide range magnification, downsizing, and electrical power saving are sought in order to accommodate a photo-acceptance unit having a high density such as more than three million pixels.
Japanese Patent Application Laid Open Nos. 06-180424, 07-151967, and 09-090221 or the like propose the below described technology that is suitable for enabling a zoom lens for use in a digital camera to have a high performance and wide range magnification. Specifically, the first lens band having a positive focal length, the second lens band having a negative focal length, and the third, fourth and fifth lens bands having positive focal lengths are arranged in this order from an object side. In addition, magnification from short to long focal point ends is performed by smoothly moving the second lens band from the object side toward an image surface. Also, an image surface positional variance that accompanies such magnification is compensated by moving the fourth lens band.
However, in any one of zoom lenses described in these official gazettes, the fourth lens band moves in order to compensate the positional variance of an image surface, which accompanies the magnification, and rarely contributes to the magnification. Specifically, the second lens band substantially bears all of the magnifying function.
As a result, a moving amount of the second lens band that accompanies the magnification is large, and the first lens band steps away from an aperture diaphragm arranged in the vicinity of the third lens band. As a result, the first lens band as well as the whole lens can not avoid being large in size.
Further, in these later days, a macro mode that enables proximal photographing more than a typical proximal photographing is increasingly demanded in not only a typical camera but also a digital camera so that detail of a circuit board, a decor good such as a jewelry, and parts of a precision instrument can more sharply and distinctly be photographed.